# File lib/csv/fields_converter.rb, line 13
def initialize(options={})
  @converters = []
  @nil_value = options[:nil_value]
  @empty_value = options[:empty_value]
  @empty_value_is_empty_string = (@empty_value == "")
  @accept_nil = options[:accept_nil]
  @builtin_converters = options[:builtin_converters]
  @need_static_convert = need_static_convert?
end

# File lib/csv/fields_converter.rb, line 23
def add_converter(name=nil, &converter)
  if name.nil?  # custom converter
    @converters << converter
  else          # named converter
    combo = @builtin_converters[name]
    case combo
    when Array  # combo converter
      combo.each do |sub_name|
        add_converter(sub_name)
      end
    else        # individual named converter
      @converters << combo
    end
  end
end

# File lib/csv/fields_converter.rb, line 47
def convert(fields, headers, lineno)
  return fields unless need_convert?

  fields.collect.with_index do |field, index|
    if field.nil?
      field = @nil_value
    elsif field.is_a?(String) and field.empty?
      field = @empty_value unless @empty_value_is_empty_string
    end
    @converters.each do |converter|
      break if field.nil? and @accept_nil
      if converter.arity == 1  # straight field converter
        field = converter[field]
      else                     # FieldInfo converter
        if headers
          header = headers[index]
        else
          header = nil
        end
        field = converter[field, FieldInfo.new(index, lineno, header)]
      end
      break unless field.is_a?(String)  # short-circuit pipeline for speed
    end
    field  # final state of each field, converted or original
  end
end

# File lib/csv/fields_converter.rb, line 39
def each(&block)
  @converters.each(&block)
end

# File lib/csv/fields_converter.rb, line 43
def empty?
  @converters.empty?
end

# File lib/csv/fields_converter.rb, line 79
def need_convert?
  @need_static_convert or
    (not @converters.empty?)
end

# File lib/csv/fields_converter.rb, line 75
def need_static_convert?
  not (@nil_value.nil? and @empty_value_is_empty_string)
end